Schematics

5
5
4
4
3
3
2
2
1
1
D D
C C
B B
A A
OSCI
OSCO
DAC-
DAC-
MIC
LDO_IN
ANT
VDDIO
BAT
BT_AVDD
V-
DAC_L
OSCI
OSCOANT
V+
ON/OFF LEDB
VCOMOLDO_IN
MIC
R+L+
R+L+
LEDB
VDDIO
V-
ON/OFF
V+
DAC_G
DC
BAT
GND_A
DAC_G
L9 0R
C23
NC
D10
BLUE
X1
24MHZ-12pF-10ppm
4 1
3 2
ANT1
ANT-PIFA
1
C20
1uF
C22
1uF
X2
MICROPHONE
JB2
L
1
2
KEY6 V-
KEY4 POWER
D9
RED
C18
1uF
L8
P-ESD
JP6
BAT
1
2
KEY5 V+
C24
NC
J8
USB_SOK_1
+5V
1
D-
2
D+
3
GND
5
G
6
GND
4
G
7
G
8
JB3
R
1
2
C25
0.1uF
U1 AC6939B
USBDM/ADC11
11
USBDP/PA3/ADC10
12
DACR
13
DACL
14
DACVSS
15
ADC0/MIC/PA1
16
VDDIO
1
VBAT
2
VSSIO
8
PB2/ADC12
5
BT_AVDD
4
PB1/ADC6
6
LDO_IN
3
BT_RF
7
BT_OSCI
9
BT_OSCO
10